diff --git a/Flow.Launcher/MessageBoxEx.xaml b/Flow.Launcher/MessageBoxEx.xaml
index c7e39b97188..e56e826ac10 100644
--- a/Flow.Launcher/MessageBoxEx.xaml
+++ b/Flow.Launcher/MessageBoxEx.xaml
@@ -33,6 +33,7 @@
         </Grid.RowDefinitions>
         
         <controls:CustomWindowTitleBar
+            x:Name="TitleBar"
             Grid.Row="0"
             ShowIcon="False"
             ShowTitle="False"
diff --git a/Flow.Launcher/MessageBoxEx.xaml.cs b/Flow.Launcher/MessageBoxEx.xaml.cs
index c50c732396e..ce001bc36a2 100644
--- a/Flow.Launcher/MessageBoxEx.xaml.cs
+++ b/Flow.Launcher/MessageBoxEx.xaml.cs
@@ -20,6 +20,11 @@ private MessageBoxEx(MessageBoxButton button)
         {
             _button = button;
             InitializeComponent();
+
+            // For YesNo dialogs, hide the close button to match native windows message box behavior
+            // https://learn.microsoft.com/en-us/dotnet/api/system.windows.messageboxbutton?view=windowsdesktop-10.0#remarks
+            if (_button == MessageBoxButton.YesNo)
+                TitleBar.ShowCloseButton = false;
         }
 
         public static MessageBoxResult Show(
@@ -52,6 +57,11 @@ public static MessageBoxResult Show(
                     _ = SetImageOfMessageBoxAsync(icon);
                 }
                 SetButtonVisibilityFocusAndResult(button, defaultResult);
+
+                // This ensures that if the message box is closed without using the answer buttons
+                // It will still have a meaningful result based on its type
+                _result = msgBox.DefaultCloseResult;
+
                 msgBox.ShowDialog();
                 return _result;
             }
@@ -158,15 +168,30 @@ private async Task SetImageAsync(string imageName)
             Img.Source = imageSource;
         }
 
+        // What the result should be if the message box is closed outside of the direct response buttons - e.g title bar close button
+        // Mostly replicates System.Windows.MessageBox behavior
+        // https://learn.microsoft.com/en-us/dotnet/api/system.windows.messageboxresult#remarks
+        private MessageBoxResult DefaultCloseResult => _button switch
+        {
+            MessageBoxButton.OK => MessageBoxResult.OK,
+            MessageBoxButton.OKCancel => MessageBoxResult.Cancel,
+            MessageBoxButton.YesNoCancel => MessageBoxResult.Cancel,
+            
+            // For YesNo this should only be used in a forced close edge case (e.g. alt f4)
+            // Most callers make the mistake of checking for No instead of not Yes - so best not to return None etc
+            MessageBoxButton.YesNo => MessageBoxResult.No,
+            
+            // covers unsupported types, e.g. AbortRetryIgnore
+            _ => MessageBoxResult.None 
+        };
+
+
         private void KeyEsc_OnPress(object sender, ExecutedRoutedEventArgs e)
         {
             if (_button == MessageBoxButton.YesNo)
                 // Follow System.Windows.MessageBox behavior
                 return;
-            else if (_button == MessageBoxButton.OK)
-                _result = MessageBoxResult.OK;
-            else
-                _result = MessageBoxResult.Cancel;
+            
             DialogResult = false;
             Close();
         }
@@ -192,12 +217,12 @@ private void Button_Cancel(object sender, RoutedEventArgs e)
             e.Handled = true;
 
             if (_button == MessageBoxButton.YesNo)
-                // Follow System.Windows.MessageBox behavior
+            {
+                // For YesNo, the close button should be hidden and inaccessible.
+                App.API.LogWarn(ClassName, "Close button was invoked despite being hidden for YesNo dialog");
                 return;
-            else if (_button == MessageBoxButton.OK)
-                _result = MessageBoxResult.OK;
-            else
-                _result = MessageBoxResult.Cancel;
+            }
+
             msgBox.Close();
             msgBox = null;
         }
diff --git a/Flow.Launcher/Resources/Controls/CustomWindowTitleBar.xaml.cs b/Flow.Launcher/Resources/Controls/CustomWindowTitleBar.xaml.cs
index 05e3148a939..7048a257248 100644
--- a/Flow.Launcher/Resources/Controls/CustomWindowTitleBar.xaml.cs
+++ b/Flow.Launcher/Resources/Controls/CustomWindowTitleBar.xaml.cs
@@ -3,6 +3,7 @@
 using System.Windows;
 using System.Windows.Media;
 using System.Windows.Media.Imaging;
+using System.Windows.Shell;
 
 namespace Flow.Launcher.Resources.Controls
 {
@@ -113,6 +114,7 @@ public WindowStateChangedEventArgs(WindowState previousState, WindowState curren
 
         private Window _hostWindow;
         private WindowState _lastNonMinimizedWindowState = WindowState.Normal;
+        private bool? _savedUseAeroCaptionButtons;
 
         private Button MinimizeButtonElement => FindName("MinimizeButton") as Button;
         private Button MaximizeButtonElement => FindName("MaximizeButton") as Button;
@@ -242,6 +244,14 @@ private void AttachToHostWindow()
                 return;
             }
 
+            // Disable system caption buttons since this control provides custom ones
+            var chrome = WindowChrome.GetWindowChrome(_hostWindow);
+            if (chrome != null)
+            {
+                _savedUseAeroCaptionButtons = chrome.UseAeroCaptionButtons;
+                chrome.UseAeroCaptionButtons = false;
+            }
+
             if (IconSource is null)
             {
                 IconSource = _hostWindow.Icon ?? DefaultWindowIcon;
@@ -269,6 +279,17 @@ private void DetachFromHostWindow()
                 return;
             }
 
+            // Restore original system caption buttons if we disabled them
+            if (_savedUseAeroCaptionButtons.HasValue)
+            {
+                var chrome = WindowChrome.GetWindowChrome(_hostWindow);
+                if (chrome != null)
+                {
+                    chrome.UseAeroCaptionButtons = _savedUseAeroCaptionButtons.Value;
+                }
+                _savedUseAeroCaptionButtons = null;
+            }
+
             _hostWindow.StateChanged -= HostWindow_StateChanged;
             _hostWindow.Activated -= HostWindow_Activated;
             _hostWindow.Closed -= HostWindow_Closed;